/*
 * Copyright (c) 2007-2012, Oracle and/or its affiliates. All rights reserved.
 * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 */
/*
 * Copyright 1999-2004 The Apache Software Foundation.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
/*
 * $Id: Function3Args.java,v 1.2.4.1 2005/09/14 20:18:42 jeffsuttor Exp $
 */
package com.sun.org.apache.xpath.internal.functions;

import com.sun.org.apache.xalan.internal.res.XSLMessages;
import com.sun.org.apache.xpath.internal.Expression;
import com.sun.org.apache.xpath.internal.ExpressionOwner;
import com.sun.org.apache.xpath.internal.XPathVisitor;

/**
 * Base class for functions that accept three arguments.
 * @xsl.usage advanced
 */
public class Function3Args extends Function2Args {
    static final long serialVersionUID = 7915240747161506646L;

    /** The third argument passed to the function (at index 2).
     *  @serial  */
    Expression m_arg2;

    /**
     * Return the third argument passed to the function (at index 2).
     *
     * @return An expression that represents the third argument passed to the
     *         function.
     */
    public Expression getArg2() {
        return m_arg2;
    }

    /**
     * This function is used to fixup variables from QNames to stack frame
     * indexes at stylesheet build time.
     * @param vars List of QNames that correspond to variables.  This list
     * should be searched backwards for the first qualified name that
     * corresponds to the variable reference qname.  The position of the
     * QName in the vector from the start of the vector will be its position
     * in the stack frame (but variables above the globalsTop value will need
     * to be offset to the current stack frame).
     */
    public void fixupVariables(java.util.Vector vars, int globalsSize) {
        super.fixupVariables(vars, globalsSize);
        if (null != m_arg2)
            m_arg2.fixupVariables(vars, globalsSize);
    }

    /**
     * Set an argument expression for a function.  This method is called by the
     * XPath compiler.
     *
     * @param arg non-null expression that represents the argument.
     * @param argNum The argument number index.
     *
     * @throws WrongNumberArgsException If the argNum parameter is greater than 2.
     */
    public void setArg(Expression arg, int argNum) throws WrongNumberArgsException {

        if (argNum < 2)
            super.setArg(arg, argNum);
        else if (2 == argNum) {
            m_arg2 = arg;
            arg.exprSetParent(this);
        } else
            reportWrongNumberArgs();
    }

    /**
     * Check that the number of arguments passed to this function is correct.
     *
     *
     * @param argNum The number of arguments that is being passed to the function.
     *
     * @throws WrongNumberArgsException
     */
    public void checkNumberArgs(int argNum) throws WrongNumberArgsException {
        if (argNum != 3)
            reportWrongNumberArgs();
    }

    /**
     * Constructs and throws a WrongNumberArgException with the appropriate
     * message for this function object.
     *
     * @throws WrongNumberArgsException
     */
    protected void reportWrongNumberArgs() throws WrongNumberArgsException {
        throw new WrongNumberArgsException(XSLMessages.createXPATHMessage("three", null));
    }

    /**
     * Tell if this expression or it's subexpressions can traverse outside
     * the current subtree.
     *
     * @return true if traversal outside the context node's subtree can occur.
     */
    public boolean canTraverseOutsideSubtree() {
        return super.canTraverseOutsideSubtree() ? true : m_arg2.canTraverseOutsideSubtree();
    }

    class Arg2Owner implements ExpressionOwner {
        /**
         * @see ExpressionOwner#getExpression()
         */
        public Expression getExpression() {
            return m_arg2;
        }

        /**
         * @see ExpressionOwner#setExpression(Expression)
         */
        public void setExpression(Expression exp) {
            exp.exprSetParent(Function3Args.this);
            m_arg2 = exp;
        }
    }

    /**
     * @see com.sun.org.apache.xpath.internal.XPathVisitable#callVisitors(ExpressionOwner, XPathVisitor)
     */
    public void callArgVisitors(XPathVisitor visitor) {
        super.callArgVisitors(visitor);
        if (null != m_arg2)
            m_arg2.callVisitors(new Arg2Owner(), visitor);
    }

    /**
     * @see Expression#deepEquals(Expression)
     */
    public boolean deepEquals(Expression expr) {
        if (!super.deepEquals(expr))
            return false;

        if (null != m_arg2) {
            if (null == ((Function3Args) expr).m_arg2)
                return false;

            if (!m_arg2.deepEquals(((Function3Args) expr).m_arg2))
                return false;
        } else if (null != ((Function3Args) expr).m_arg2)
            return false;

        return true;
    }

}
